Pioneer: history and future of corn breeding

A wall of exotic corn varieties — some towering, some odd-looking — was the backdrop for a stop at the recent field day on Kip Cullers' Stark City, Mo., farm.

The varieties illustrated “some historical lines of corn down to what we're selling,” said Bill Niebur, who is based in Iowa as Pioneer vice president of crop genetics research and development.

Before domestication, corn started out as a grass with kernels that looked like “little rocks. As corn has been domesticated over thousands and thousands of years, it slowly separated. The male portion, the tassels, slowly came to the top and the ear moved to the center.

“One of the intermediate stages is this pod corn, where every kernel on this ear is surrounded by blooms,” said Niebur, holding up an ear. “It's kind of like a wheat kernel.”

So, corn progressed through different stages. As it became more and more domesticated, “farmers began selecting ears they liked and wanted to grow the following year.”

Niebur pointed to ears of Bloody Butcher — which was grown in the 1800s — and Reed Yellow Dent, an open pollinated line that was very popular in 1800s Iowa.

“Although we did a good job of selecting, many times the plant would be very inefficient, producing many husks (and other plant material) they didn't need. This particular plant is an old, open-pollinated line. Look at the tassel — it's producing millions and millions of pollen grains. More pollen than it needs to pollinate the ear.”

Meanwhile, Pioneer hybrids currently being sold have “one main spike and two branches. That's all it needs. As plant breeders, we've bred the (extra) tassel off it because it was inefficient.” Breeders have also changed the leaf architecture. “The old lines have leaves that are very floppy and top leaves intercept light and the bottom leaves aren't doing anything as far as supporting photosynthate for that ear.

“This is 33K44, which is a line we currently sell in Missouri. You can see how upright the leaves are compared to this plant. This allows us to put more plants in an acre and better intercept the light. With the added benefits of stronger roots and stalk, we've allowed the plant to handle a lot more stress.”

Something else of interest: the yield of a single ear on a single plant basis “hasn't really changed over decades and decades of plant breeding.”

Having looked back, where is corn breeding headed?

“Well, we need to increase agricultural productivity,” said Gary Henke, Pioneer research scientist based in Miami, Mo. The world is saying we need more corn and soybeans.

“What we need to do as a research organization — in combination with agriculturalists and end users — is translate the genetic potential that farms like Kip's tell us that corn possesses into national averages. Then, we'll provide the grain the world so desperately needs.”

In order to attack that genetic gain challenge, the breeders will “add in not only the best genes we have from this diverse array of genes we have in our collection,” said Henke, pointing to the exotic corns behind him, “but combine it with Bt technology and modern herbicide tolerance technology to avoid weed competition.” And, for the next generation “we'll increase the plant's ability to create more yield with less — less nitrogen, or water.”

Questions and concerns of farmers have shifted since Henke began his career 25 years ago. “The most frequent question I was asked for the first 23 years was, ‘Why do you keep making more corn? We've got piles of it everywhere and we have no idea what to do with it.’ The last two and a half years, no one has asked that question.

“Now the question is, ‘Can you globally increase maize productivity at a rate that will sustain it as an agricultural input? Or, will there be new demands that continue to emerge?’”

The future is bright, said Henke.

“Today, we see the power of genetics combined with the power of our breeding programs combined with the talent we've amassed. In the last (18 months), we've hired 670 people (in research and development) to, basically, work on increasing agricultural productivity through genetics and technology.”

In a more limited yield environment is there any relationship between plant height/size and yield?

“Definitely,” said Niebur. “Generally, plants grown in a drier climate (are) water stressed and try to conserve water. They don't (grow large).”

Conversely, the same hybrid grown in water-rich areas creates “totally different plant architecture just from the environment the plant (experiences).

“Last night, a guy asked me why not breed dwarf corn — sorghum with an ear? We don't have that germ plasm today, but that's a possibility.”

One of the challenges for Pioneer “is to identify how to lead the market so we get there with the right product when it's necessary and required,” said Henke. “If we hadn't done the work we did in the 1990s on insect resistance and herbicide tolerance, imagine where we'd be today in terms of trying to meet the global productivity challenges.

“That's why, when there was $2 or $1.80 commodity corn, people were saying, ‘Yeah, we understand this whole profitability thing and you're trying to eliminate inputs. But at that time in the 1990s, it was about reducing inputs.”

Now, the challenge is “stabilization of production, quality grain and higher productivity — creating virtual acres. If we can double the yield on every acre, we can move on and don't have to put highly erodible soil into production. That's what we're after and we're investing a lot of time and talent.”